Depending on the type of LinkedIn membership (free or paid) and connection (e.g. 1st degree, 2nd degree, 3rd degree or Group) you have, LinkedIn will show you the person’s:

Full first and last names… or their just first name and the initial of their last name

Full profile or a profile summary (Profile summaries are just a portion of the full profile, and it’s generally not enough information to determine if someone can provide the advice or assistance you want.)

Because you’ll usually want to read a person’s full profile, you’ll frequently need to use a different strategy to gain access to a person’s full LinkedIn profile and their full first and last names.